"How do we walk by faith? How do we walk by the Spirit?"

How do we walk by faith and not by feelings? Aaron made an excuse for his sin, and God didn't punish Him? How can I know that God's gospel promises are for me individually? What do you think of Billy Graham? Is the Bible on audio a good approach to learning more? How do we walk by the Spirit consistently? What tools do we need? My wife and mother passed away on the same day a year ago. I can't help but think sometimes that it was God trying to tell me something; and it's just a lot to grieve all at once.